For example, desulfurization facilities are installed in a thermal power station and the like for removing sulfur oxides in flue gas generated when fuel oil, coal, and the like are subjected to combustion using a combustor. Examples of the desulfurization facilities include a wet flue gas desulfurization apparatus that brings flue gas into contact with an absorbent (liquid including a calcium compound such as limestone) in an absorber to absorb sulfur oxides in the flue gas into the absorbent, and generates gypsum as a by-product by oxidizing the absorbent after being brought into contact with the flue gas and performing solid-liquid separation.
In this wet flue gas desulfurization apparatus, a sulfur dioxide (SO2) as a sulfur compound (hereinafter, also referred to as “S-containing compound”) in the flue gas to be introduced is brought into contact with the absorbent to transfer the SO2 to the absorbent, and the flue gas is cleaned. The SO2 transferred to the absorbent becomes a sulfite ion in the absorbent.
The wet flue gas desulfurization apparatus introduces air into the absorbent, oxidizes the sulfite ion in the absorbent into a sulfate ion, processes the sulfate ion in the absorbent thereafter, and collects the processed sulfate ion as gypsum, for example. In the wet flue gas desulfurization apparatus, as a device for supplying air for oxidation into a tank, used is a water flow oxidation device that supplies the absorbent and air to an absorbent storage tank that stores the absorbent.
As this water flow oxidation device, developed is a gas-liquid mixing device that performs oxidation and stirring within the absorbent storage tank using jetting water streams jetted from a plurality of jet air spargers (JASs) (Patent Literature 1).